The short message service is the most active service in the mobile value-added services, which has been increased constantly at a higher rate in recent years. The holiday characteristics of the short message service are also especially evident. In holidays such as the Spring Festival, the peak of service flow even comes up to 10 times the peak of regular flow or even more. As a result, huge resources such as the MSC (Mobile Switching Center), the BSS (Base Station System) and the paging channel are occupied, and other services such as the voice service are affected.z
So far, the devices of SMS message center from each manufacturer are able to support the downlink (terminated) flow control to a certain degree. The method in use usually sets a fixed flow threshold for each MSC, and transfers in unit time granularity the downlink short messages whose number is within the threshold; those surpassing the threshold stops being sent, and the SMS message center directly modifies the status of the short messages to be “temporarily failed” to wait for retransmission or directly discards them.
The mobile network provides service for a plurality of services such as voice and SMS simultaneously, and system resources occupied by each service are different. The network load is decided by the sum of all services actually used by the users. So far, there is no mature and accurate service resource model established to address this issue, that is, whether the operation status of the MSC network element is blocking or not is related to the number of short message services, but the quantitative relationship cannot be accurately obtained in advance. Therefore, the MSC flow threshold is often preset as a fixed value by personal experiences, which might easily cause the threshold at certain times so big that the MSC still keeps transferring many short messages while it is very busy, which has a great impact on the MSC and occupies system and wireless resources, thus the purpose of the flow control cannot be achieved; sometimes the threshold is set so small that the message center suspends sending a lot of to-be-sent shot messages since the MSC is misjudged as busy when the MSC is actually idle, thus the available network resources are wasted and user service experience is affected.